The basic purpose underlying the proposed research is to seek evidence for general priniciples that may determine memory processes (response availability or response dominance) in both the classical conditioning and the verbal learning fields. To do this, we propose to apply to a perceptual-motor, classical conditioning situation the interference paradigms that have been found effective in verbal learning research. Cats, shaped to hang quietly in a suspended sling, are our subjects. We have two possible conditioned stimuli, a light or a tone; and two available conditioned responses, the flexion of the right forepaw or the flexion of the left. With shock as the UCS, such conditioned responses can be unambiguously acquired, and clearly read. By means of manipulation of the two conditioned stimuli and the two conditioned responses, verbal learning paradigms can be successfully mimicked. Specifically, we plan to observe, between groups, the effect of the interpolated learning (conditioning) of three different paradigms on the original learning of a different paradigm. We propose to measure these effects by retention tests on original learning and by savings scores in relearning, after two different retention intervals: (1) when test for memory of the first-learned CR occurs immediately after the interpolated learning; and (2) when it occurs six weeks after the end of interpolated learning. We also propose to investigate interference effects when the cats concurrently learn two different conditioned responses to two different conditioned stimuli.